Artículos con la etiqueta ‘óptica’

Particles, waves and trajectories: 210 years after Young’s experiment

Por • 20 feb, 2014 • Category: Leyes

Mermin’s «shut up and calculate!» somehow summarizes the most widely accepted view on quantum mechanics. This conception has led to a rather constraining way to think and understand the quantum world. Nonetheless, a closer look at the principles and formal body of this theory shows that, beyond longstanding prejudices, there is still room enough for alternative tools. This is the case, for example, of Bohmian mechanics. As it is discussed here, there is nothing contradictory or wrong with this hydrodynamical representation, which enhances the dynamical role of the quantum phase to the detriment (to some extent) of the probability density. The possibility to describe the evolution of quantum systems in terms of trajectories or streamlines is just a direct consequence of the fact that Bohmian mechanics (quantum hydrodynamics) is just a way to recast quantum mechanics in the more general language of the theory of characteristics.

Experimental demonstration of metamaterial multiverse in a ferrofluid

Por • 2 feb, 2013 • Category: Ambiente

Extraordinary light rays propagating inside a hyperbolic metamaterial look similar to particle world lines in a 2+1 dimensional Minkowski spacetime [1]. Magnetic nanoparticles in a ferrofluid are known to form nanocolumns aligned along the magnetic field, so that a hyperbolic metamaterial may be formed at large enough nanoparticle concentration nH. Here we investigate optical properties of such a metamaterial just below nH. While on average such a metamaterial is elliptical, thermal fluctuations of nanoparticle concentration lead to transient formation of hyperbolic regions (3D Minkowski spacetimes) inside this metamaterial. Thus, thermal fluctuations in a ferrofluid look similar to creation and disappearance of individual Minkowski spacetimes (universes) in the cosmological multiverse. This theoretical picture is supported by experimental measurements of polarization-dependent optical transmission of a cobalt based ferrofluid at 1500 nm.

Consiguen mover objetos a distancias métricas utilizando sólo la luz

Por • 5 oct, 2010 • Category: Ciencia y tecnología, física

Un equipo de investigadores ha logrado desplazar partículas en el aire, a lo largo de distancias métricas utilizando únicamente la luz. Hasta ahora, se había conseguido mover objetos con láser pero a distancias mínimas, de tan sólo varios cientos de micrómetros. El logro obtenido, que ha sido demostrado en pruebas de laboratorio, permitirá el transporte sin contacto de contenedores de sustancias peligrosas o sensibles, como virus, células vivas o gases, entre otras aplicaciones.